Role of Major Forest Biomes in Climate Change Mitigation …
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tidal waves (Ninawe et al. 2018). The complex coral reef ecosystems are projected
to decline on a large scale by 2050 (Baker et al. 2008; Bhattarai 2017). Mangrove
forests are known to respond to climate change by landward migration, which poses a
threat to other coastal habitats like salt marshes (Satyanarayana et al. 2013; Bhattarai
2017). It has been predicted that there would be a reduction in mangrove forests for
about 10–20% by 2100 (Danovaro et al. 2008; Bhattarai 2017). Hence, biodiversity
and ecosystem services would continue to be impacted and impaired for several years
to come because of climate change.
2.2 Range Shifts
Biogeographic range expansions or contractions occur due to the increase or decrease
in the climatically suitable areas (Jackson and Overpeck 2000; Garcia et al. 2014)
and such range shift is a means of an evolutionary, adaptive strategy for survival of
organisms (Pitelka 1997; Drielsma et al. 2017). The most basic and often observed
response to global warming and climate change is upslope and poleward shifts in
species’ habitat ranges (Parmesan et al. 1999; Hannah and Bird 2018) and species
tend to undergo long-distance latitudinal shifts towards the poles when upslope movements were constrained by other factors or not possible. The species in the northern
hemisphere move northwards and those in the southern hemisphere move southwards
(Hannah and Bird 2018). It has been estimated that terrestrial taxa shift towards pole
at the rate of 17 km per decade, while marine taxa move at the rate of 72 km per
decade (Sorte et al. 2010; Poloczanska et al. 2013; Pecl et al. 2017). Lower altitude
species are shifting upwards to higher elevations and the higher altitude species are
constantly restructuring their community relationships (Woodward et al. 2010; Bhattarai 2017). Biogeographic range shifts also occur during stable climatic conditions,
where organisms migrate in search of food, water and other resources based on their
physiological needs (Pitelka 1997). Species that cannot adapt in the changing climatic conditions and require wet and cool habitats undergo range contractions and
finally become extinct (Thomas et al. 2004; Drielsma et al. 2017). With increasing
anthropogenic disturbances, climate change favours weedy and opportunistic species,
whereas, those that are niche specific become trapped (Hannah and Bird 2018). The
ability of a species to shift its range to a new location depends on timely availability
of a new environment with enough resources that would support the species’ establishment (Pitelka 1997; Hoegh-Guldberg et al. 2008; Drielsma et al. 2017). Further,
a species’ ability to shift its range in response to climate change depends on their
ecological and evolutionary characteristics (Dawson et al. 2011; Bhattarai 2017).
However, establishing new populations at the leading edge of the range expansion in
new habitats tend to lead to genetic bottlenecks over time, potentially lowering the
adaptive ability of the population to future climate change scenario (Nei et al. 1975).
On the other hand, range contractions also lower genetic diversity and are likely to
face extinction (Rubidge et al. 2012; Staudinger et al. 2012). Furthermore, interspecific hybridization may allow a species to persist in a changing climate, which leads
487
tidal waves (Ninawe et al. 2018). The complex coral reef ecosystems are projected
to decline on a large scale by 2050 (Baker et al. 2008; Bhattarai 2017). Mangrove
forests are known to respond to climate change by landward migration, which poses a
threat to other coastal habitats like salt marshes (Satyanarayana et al. 2013; Bhattarai
2017). It has been predicted that there would be a reduction in mangrove forests for
about 10–20% by 2100 (Danovaro et al. 2008; Bhattarai 2017). Hence, biodiversity
and ecosystem services would continue to be impacted and impaired for several years
to come because of climate change.
2.2 Range Shifts
Biogeographic range expansions or contractions occur due to the increase or decrease
in the climatically suitable areas (Jackson and Overpeck 2000; Garcia et al. 2014)
and such range shift is a means of an evolutionary, adaptive strategy for survival of
organisms (Pitelka 1997; Drielsma et al. 2017). The most basic and often observed
response to global warming and climate change is upslope and poleward shifts in
species’ habitat ranges (Parmesan et al. 1999; Hannah and Bird 2018) and species
tend to undergo long-distance latitudinal shifts towards the poles when upslope movements were constrained by other factors or not possible. The species in the northern
hemisphere move northwards and those in the southern hemisphere move southwards
(Hannah and Bird 2018). It has been estimated that terrestrial taxa shift towards pole
at the rate of 17 km per decade, while marine taxa move at the rate of 72 km per
decade (Sorte et al. 2010; Poloczanska et al. 2013; Pecl et al. 2017). Lower altitude
species are shifting upwards to higher elevations and the higher altitude species are
constantly restructuring their community relationships (Woodward et al. 2010; Bhattarai 2017). Biogeographic range shifts also occur during stable climatic conditions,
where organisms migrate in search of food, water and other resources based on their
physiological needs (Pitelka 1997). Species that cannot adapt in the changing climatic conditions and require wet and cool habitats undergo range contractions and
finally become extinct (Thomas et al. 2004; Drielsma et al. 2017). With increasing
anthropogenic disturbances, climate change favours weedy and opportunistic species,
whereas, those that are niche specific become trapped (Hannah and Bird 2018). The
ability of a species to shift its range to a new location depends on timely availability
of a new environment with enough resources that would support the species’ establishment (Pitelka 1997; Hoegh-Guldberg et al. 2008; Drielsma et al. 2017). Further,
a species’ ability to shift its range in response to climate change depends on their
ecological and evolutionary characteristics (Dawson et al. 2011; Bhattarai 2017).
However, establishing new populations at the leading edge of the range expansion in
new habitats tend to lead to genetic bottlenecks over time, potentially lowering the
adaptive ability of the population to future climate change scenario (Nei et al. 1975).
On the other hand, range contractions also lower genetic diversity and are likely to
face extinction (Rubidge et al. 2012; Staudinger et al. 2012). Furthermore, interspecific hybridization may allow a species to persist in a changing climate, which leads